In a navigation device for a vehicle, it is generalized such that a flash memory is used for a memory (refer to patent document No. 1). This flash memory includes a flash memory for a boot device that stores an IPL (i.e., Initial Program Loader), a OS (i.e., Operating System) and an application program, and a flash memory for a map media. Since the flash memory for the boot device is a NOR type flash memory, the dimensions of the memory are large, and a cost of the memory is high. On the other hand, a NAND type flash memory used for the flash memory for the map media has small dimensions of the memory, and the capacity of the memory increases with low cost. Thus, when the NAND type flash memory is used for the boot device, the cost can be reduced.
[Patent document No. 1] JP-A-H09-182010
However, the NAND type flash memory includes an inherent failure block in memory blocks of the flash memory. Further, when the flash memory is operated, a failure block is generated. Thus, a memory card controller controls not to use the failure block. Further, since the NAND type flash memory has a limitation of the number of rewriting times, the memory card controller controls the number of rewriting times.
In the NAND type flash memory such as a SD card, in order to control the above described failure block and the number of rewriting times, the memory card controller executes various processes such as a search process of all flash memories and a process for searching a convert table stored in the flash memory when a power source turns on (i.e., when an accessory switch turns on). Thus, an initial setting process time is long, for example, 1 seconds at a maximum, which is an actual measurement result. Accordingly, when the SD card is used for the boot device, for example, the CPU cannot access the flash memory while the memory card controller executes the initial setting process. Accordingly, the reading step of the CPU for reading the IPL from the flash memory at the beginning is delayed. Thus, activation of a soft ware such as the OS is delayed, and therefore, a response to communication with an in-vehicle LAN may not be ready in time.